中文摘要：

细胞膜质微区（microdomain）是细胞膜上特殊的结构域，在细胞信号转导和物质运输过程中起着非常重要的作用．绝大多数膜质微区来源于全细胞膜，即包括质膜和细胞器膜．最新研究表明细胞器膜如高尔基体膜也有膜质微区，因此分离了猪心肌浆网膜的膜质微区．首先获得了没有质膜污染的猪心肌浆网，用去污剂Triton X-100处理该肌浆网，获得了去污剂不溶的质膜微区（SR-DRM），该微区富集胆固醇和鞘磷脂．质膜微区的标记脂和蛋白质：神经节苷脂GM1和Caveolin-3也在该区富集．同时还研究了心肌浆网Ca^2＋-ATPase（SERCA2a）的分布，结果表明，相当数量的SERCA2a分布在膜质微区，并且有正常的生理功能．上述研究结果表明，在心肌浆网膜上有膜质微区的存在，进一步证明膜质微区不仅存在于细胞质膜，也普遍存在于细胞器膜．

英文摘要：

It is generally believed that sphingomyelin- and cholesterol-enriched microdomains can be isolated as detergent-resistant membranes （DRMs） from plasma membrane and organelle membranes. Here the isolation of microdomains from porcine cardiac sarcoplasmic reticulum （SR） membranes is described. These SR-derived detergent-resistant membranes （SR-DRMs） enriched in sphingomyelin and cholesterol have a low buoyant density. Both ganglioside GM1 and caveolin-3 in the SR, known as a marker protein ofcaveolae at plasma membrane are present in the SR-DRMs. It was demonstrated that significant amount of SERCAs together with caveolin-3 associates with SR-DRMs, and are fully functional. The results suggested that SR membranes like other biomembranes, such as the plasma membrane, contained microdomains.